This application is a 371 of PCT/IB99/00259 filed Feb. 15, 1999.
This invention relates to 2-heteroaryl-pyrrolidine, -piperidine and -homopiperidine derivatives and to processes for the preparation of, intermediates used in the preparation of, compositions containing and the uses of, such derivatives.
It has been reported that the immunosuppressant FK-506 promotes neurite outgrowth in vitro in neuronal cell line and culture models (see Lyons et al, Pro. Natl. Acad. Sci., 1994, 91, 3191-95 and Snyder et al, Nature Medicine, 1995, 1, 32-37). WO-A-96/40140, WO-A-96/40633 and WO-A-97/16190 disclose compounds that have neurotrophic activity but which lack inhibitory action at the protein phosphatase calcineurin and therefore which have no immunosuppressive activity.
It has been suggested in WO-A-96/40140 and WO-A-96/40633 that the neurotrophic effect of these compounds is mediated, at least in part, by a high affinity interaction with the FK-506 binding proteins, such as FKBP-12, or FKBP-52. However, the mechanism by which this interaction with FKBP-type immunophilins results in a neurotrophic effect is at present unknown. The range of neurotrophic activity that can be realised through this neurotrophic/non-immunosuppressant class of compounds has been explored and it has been found that axon regeneration can be promoted after facial nerve crush and sciatic nerve crush in the rat. It has also been observed that the functional regeneration of dopamine neurons damaged with the toxin MPTP was promoted by the compounds disclosed therein in mice. Additionally, it was reported that restoration of striatal innervation in the rat was promoted by the compounds disclosed therein following 6-hydroxydopamine lesioning of dopaminergic neurons (see Hamilton and Steiner, Current Pharmaceutical Design, 1997, 3, 405-428).
It has now been found that the present compounds are neurotrophic agents which have an affinity for FKBP-type immunophilins. In particular, they are potent inhibitors of the enzyme activity and especially of the cis-trans prolyl isomerase (rotamase) activity of FKBP-type immunophilins, particularly the immunophilin FKBP-12. The present compounds do not significantly inhibit the protein phosphatase calcineurin and therefore lack any significant immunosuppressive activity.
The present compounds therefore moderate neuronal degeneration and promote neuronal regeneration and outgrowth and can be used for treating neurological disorders arising from neurodegenerative diseases or other disorders involving nerve damage. The neurological disorders that may be treated include senile dementia (Alzheimer""s disease) and other dementias, amyotrophic lateral sclerosis and other forms of motor neuron disease, Parkinson""s disease, Huntington""s disease, neurological deficits associated with stroke, all forms of degenerative disease affecting the central or peripheral nervous system (e.g. cerebellar-brainstem atrophies, syndromes of progressive ataxias), all forms of muscular dystrophy, progressive muscular atrophies, progressive bulbar muscular atrophy, physical or traumatic damage to the central or peripheral nervous system (e.g. spinal cord), hemiated, ruptured or prolapsed intervertebrae disc syndromes, cervical spondylosis, plexus disorders, thoracic outlet syndromes, all forms of peripheral neuropathy (both diabetic and non-diabetic), trigeminal neuralgia, glossopharyngeal neuralgia, Bell""s Palsy, all forms of auto-immune related disease resulting in damage of the central or peripheral nervous system (e.g. multiple sclerosis, myasthenia gravis, Guillain-Barrxc3xa9 syndrome), AIDS related disorders of the nervous system, dapsone ticks, bulbar and retrobulbar affections of the optic nerve (e.g. retinopathies and retrobulbar neuritis), hearing disorders such as tinnitus, and prion diseases.
Preferably, the present compounds can be used for treating senile dementia (Alzheimer""s disease) or another dementia, amyotrophic lateral sclerosis or another form of motor neuron disease, Parkinson""s disease, Huntingdon""s disease, a neurological deficit associated with stroke, physical or traumatic damage to the central or peripheral nervous system (e.g. spinal cord), a peripheral neuropathy (either diabetic or non-diabetic), multiple sclerosis or a hearing disorder such as tinnitus.
The present invention provides a compound of the formula: 
or a pharmaceutically acceptable salt or solvate thereof, wherein
R1 is a 5- or 6-membered ring heteroaryl group containing either 1, 2, 3 or 4 nitrogen heteroatoms, or 1 oxygen or sulphur heteroatom and, optionally, 1 or 2 nitrogen heteroatoms, said heteroaryl group being linked to the adjacent carbon atom by a ring carbon atom and optionally substituted by from 1 to 3 substituents each independently selected from C1-C6 alkyl, C2-C6 alkenyl, xe2x80x94Xxe2x80x94(C3-C7 cycloalkyl), xe2x80x94X-aryl, xe2x80x94X-het, xe2x80x94Xxe2x80x94OH, xe2x80x94Xxe2x80x94(C1-C4alkoxy), xe2x80x94Xxe2x80x94CO2R5, xe2x80x94Xxe2x80x94CN, and xe2x80x94Xxe2x80x94NR3R4;
R2 is H, phenyl or C3-C7 cycloalkyl, said phenyl or cycloalkyl being optionally benzo- or C3-C7 cycloalkyl-fused and optionally substituted, including in the benzo- or cycloalkyl-fused portion, by from 1 to 3 substituents each independently selected from C1-C6 alkyl, C1-C6 alkoxy, xe2x80x94OH, xe2x80x94(C1-C6 alkylene)OH, halo and halo(C1-C6 alkylene)xe2x80x94,
or R2 is a 5-, 6- or 7-membered ring heterocyclic group containing either 1, 2, 3 or 4 nitrogen heteroatoms, or 1 oxygen or sulphur heteroatom and, optionally, 1 or 2 nitrogen heteroatoms, said heterocyclic group being saturated or partially or fully unsaturated, optionally benzo-fused and optionally substituted, including in the benzo-fused portion, by from 1 to 3 substituents each independently selected from C1-C6 alkyl, C1-C6 alkoxy, halo, halo(C1-C6 alkylene)xe2x80x94 and xe2x80x94CO2R5; said R2 group being attached to W by any mono- or bicyclic ring carbon atom or heteroatom;
R3 and R4 are either each independently selected from H, C1-C6 alkyl, C3-C6 cycloalkyl and xe2x80x94(C1-C6 alkylene)(C3-C6 cycloalkyl), or, when taken together, represent unbranched C3-C6 alkylene optionally containing O or NR5;
R5 is H, C1-C6 alkyl, C3-C6 cycloalkyl, xe2x80x94(C1-C6 alkylene)(C3-C6 cycloalkyl) or xe2x80x94(C1-C6 alkylene)aryl;
A is unbranched C3-C5 alkylene optionally substituted by C1-C6 alkyl;
W is a direct link, C1-C6 alkylene or C2-C6 alkenylene;
X is a direct link, C1-C6 alkylene or xe2x80x94(C0-C6 alkylene)xe2x80x94Zxe2x80x94(C0-C6 alkylene)xe2x80x94;
Y is SO2 , carbonyl, xe2x80x94CONR5xe2x80x94, xe2x80x94CO.COxe2x80x94, xe2x80x94CH2COxe2x80x94, xe2x80x94CS.COxe2x80x94, xe2x80x94CO.CSxe2x80x94 or xe2x80x94CO.CH(OH)xe2x80x94;
Z is O, S, xe2x80x94CR5NR3R4xe2x80x94, xe2x80x94CR5NR5(CO2R5)xe2x80x94, xe2x80x94CR5(aryl1)xe2x80x94, xe2x80x94NR5xe2x80x94, xe2x80x94NR5CO2xe2x80x94, xe2x80x94CONR5xe2x80x94 or xe2x80x94NR5COxe2x80x94;
xe2x80x9carylxe2x80x9d is phenyl optionally substituted by from 1 to 3 substituents each independently selected from C1-C6 alkyl, xe2x80x94(C1-C6 alkylene)OH, C1-C6 alkoxy, xe2x80x94(C1-C6 alkylene)(C1-C6 alkoxy), halo, halo(C1-C6 alkylene)xe2x80x94, xe2x80x94NR3R4, xe2x80x94(C1-C6 alkylene)NR3R4, xe2x80x94O(C1-C6 alkylene)NR3R4 and xe2x80x94(C1-C6 alkylene)(phthalimido);
xe2x80x9carylxe2x80x9d is phenyl optionally substituted by from 1 to 3 substituents each independently selected from C1-C6 alkyl, C1-C6 alkoxy, xe2x80x94(C1-C6 alkylene)(C1-C6 alkoxy), halo and halo(C1-C6 alkylene)xe2x80x94; and
xe2x80x9chetxe2x80x9d is a 5-, 6- or 7-membered ring heterocyclic group containing either 1, 2, 3 or 4 nitrogen heteroatoms, or 1 oxygen or sulphur heteroatom and, optionally, 1 or 2 nitrogen heteroatoms, said heterocyclic group being saturated or partially or fully unsaturated, or xe2x80x9chetxe2x80x9d is azetidinyl, said xe2x80x9chetxe2x80x9d being optionally substituted by from 1 to 3 substituents each independently selected from C1-C6 alkyl, xe2x80x94(C1-C6 alkylene)(C3-C7 cycloalkyl), C1-C6 alkoxy, C3-C7 cycloalkyl, xe2x80x94(C1-C6 alkylene)(C1-C6 alkoxy), halo, halo(C1-C6 alkylene)xe2x80x94, xe2x80x94NR3R4, xe2x80x94CO2R5, xe2x80x94(C1-C6 alkylene)aryl and xe2x80x94(C1-C6 alkylene)NR3R4:
with the provisos that
(a) the heteroaryl group of R1 is not substituted by xe2x80x94(C0-C6 alkylene)xe2x80x94Zxe2x80x94(C0 alkylene)(xe2x80x94OH or xe2x80x94C1-C4alkoxy or xe2x80x94CN or xe2x80x94NR3R4) when Z is O, S, xe2x80x94NR5xe2x80x94, xe2x80x94NR5CO2 xe2x80x94 or xe2x80x94CONR5xe2x80x94; and
(b) when W is a direct link, R2 is only H when Y is xe2x80x94CONR5xe2x80x94;
(c) when A is C3 alkylene, Y is sulphonyl, W is a direct link, and R2 is para methyl substituted phenyl, then R1 is not 
(d) when A is C4 alkylene, Y is carbonyl, W is C, alkylene and R2 is H, then R1 is not 
(e) when A is C4 alkylene, Y is carbonyl, W is a direct link and R2 is 3-hydroxy phenyl,
xe2x80x83then R1 is not 
(f) when A is C3 alkylene, Y is carbonyl, W is a direct link and R2 is phenyl, then R1 is not 2-furyl.
Disclaimers (c) to (f) are based on the following documents: Agr. Biol. Chem. (1971), 35(10), 1572-7; Tetrahedron Lett. (1981), 22(2), 141-4; WO-A-9703973 published Feb. 6, 1997 and Chemical Abstracts, vol. 56, no. 11, abstract no. 13001g.
With the aforementioned disclaimers (c ) to (f), the aforementioned compounds for formula (I) are novel. However, if one or more broader disclaimers are required for validity they may be based on the following disclaimers:
(c) wherein when A is C3 alkylene and Y is sulphonyl, W is a direct link, and R2 is substituted phenyl, then R1 is not a diamino substituted triazine (relates to aforementioned disclaimer (c));
(d) wherein Yxe2x80x94Wxe2x80x94R1 does not represent a C1-C4 acyl group, when R1 is an optionally substituted furanyl group (relates to aforementioned disclaimers (d) and (f)); and
(e) wherein R1 is not an oxazole disubstituted by aryl (relates to aforementioned disclaimer (e)).
Throughout the above definitions, xe2x80x9chaloxe2x80x9d means fluoro, chloro, bromo or iodo and alkyl, alkoxy, alkenyl, alkylene and alkenylene groups containing the requisite number of carbon atoms, except where indicated, can be unbranched- or branched-chain.
When R3 and R4, when taken together, represent unbranched C3-C6 alkylene optionally containing O or NR5, the heteroatom may be positioned either at a terminal position of, or in an intermediate position in, the unbranched C3-C6 alkylene group. Examples of such xe2x80x94NR3R4 groups include piperazino and morpholino.
The pharmaceutically acceptable salts of the compounds of the formula (I) include the acid addition and the base salts thereof.
Suitable acid addition salts are formed from acids which form non-toxic salts and examples are the hydrochloride, hydrobromide, hydroiodide, sulphate, bisulphate, nitrate, phosphate, hydrogen phosphate, acetate, maleate, fumarate, lactate, tartrate, citrate, gluconate, succinate, saccharate, benzoate, methanesulphonate, ethanesulphonate, benzenesulphonate, p-toluenesulphonate and pamoate salts.
Suitable base salts are formed from bases which form non-toxic salts and examples are the sodium, potassium, aluminium, calcium, magnesium, zinc and diethanolamine salts.
For a review on suitable salts see Berge et al, J. Pharm. Sci., 1977, 66, 1-19.
The pharmaceutically acceptable solvates of the compounds of the formula (I) include the hydrates thereof.
Also included within the present scope of the compounds of the formula (I) are polymorphs and radiolabelled derivatives thereof.
A compound of the formula (I) contains one or more asymmetric carbon atoms and therefore exists in two or more stereoisomeric forms. Where a compound of the formula (I) contains an alkenyl or alkenylene group, cis (E) and trans (Z) isomerism may also occur. The present invention includes the individual stereoisomers of the compounds of the formula (I) and, where appropriate, the individual tautomeric forms thereof, together with mixtures thereof.
Separation of diastereoisomers or cis and trans isomers may be achieved by conventional techniques, e.g. by fractional crystallisation, chromatography or H.P.L.C. of a stereoisomeric mixture of a compound of the formula (I) or a suitable salt or derivative thereof. An individual enantiomer of a compound of the formula (I) may also be prepared from a corresponding optically pure intermediate or by resolution, such as by H.P.L.C. of the corresponding racemate using a suitable chiral support or by fractional crystallisation of the diastereoisomeric salts formed by reaction of the corresponding racemate with a suitable optically active acid or base, as appropriate.
Particularly preferred are compounds of the formula (Ixe2x80x2): 
wherein R1, R2, A, W and Y are as previously defined for a compound of the formula (I).
In the above definitions of a compound of the formula (I) and (Ixe2x80x2), the following definitions are preferred.
Preferably, R1 is triazolyl, isoxazolyl, oxadiazolyl, tetraazolyl, thiazolyl or thiadiazolyl, that is linked to the adjacent carbon atom by a ring carbon atom and optionally substituted by 1, 2 or 3 substituents each independently selected from C1-C6 alkyl, xe2x80x94X-aryl, xe2x80x94X-het, xe2x80x94Xxe2x80x94CO2R5 and xe2x80x94Xxe2x80x94NR3R4.
More preferably, R1 is triazolyl, isoxazolyl, oxadiazolyl, tetraazolyl, thiazolyl or thiadiazolyl, that is linked to the adjacent carbon atom by a ring carbon atom and optionally substituted by 1, 2 or 3 substituents each independently selected from C1-C6 alkyl, xe2x80x94X-aryl, xe2x80x94X-het, xe2x80x94Xxe2x80x94CO2R5 and xe2x80x94Xxe2x80x94NR3R4, wherein
X is a direct link, C1-C6 alkylene or xe2x80x94(C0-C6 alkylene)xe2x80x94Zxe2x80x94(C0-C6 alkylene)xe2x80x94;
Z is O, xe2x80x94CR5NR3R4, xe2x80x94CR5NR5(CO2R5)xe2x80x94, xe2x80x94NR5xe2x80x94 or xe2x80x94NR5CO2xe2x80x94;
xe2x80x9carylxe2x80x9d is phenyl optionally substituted by from 1 to 3 substituents each independently selected from xe2x80x94(C1-C6 alkylene)NR3R4, xe2x80x94Oxe2x80x94(C1-C6 alkylene)NR3R4, xe2x80x94(C1-C6 alkylene)(phthalimido) and xe2x80x94(C1-C6 alkylene)OH;
xe2x80x9chetxe2x80x9d is piperidyl, pyrazinyl, furyl, piperazinyl, pyrimidinyl or morpholinyl, optionally substituted by from 1 to 3 xe2x80x94(C1-C6 alkylene)aryl, xe2x80x94(C1-C6 alkylene)(C3-C7 cycloalkyl) substituents, or xe2x80x94CO2R5 where R5 is xe2x80x94(C1-C6 alkylene)aryl or C1-C6 alkyl; or xe2x80x94(C1-C6 alkylene)NR3R4 where xe2x80x9chetxe2x80x9d is furyl;
R3 and R4 are either each independently selected from H and C1-C6 alkyl or, when taken together, represent unbranched C3-C6 alkylene; and
R5 is H or C1-C6 alkyl.
Yet more preferably, R1 is 1,2,4-triazolyl, isoxazolyl, 1,2,4-oxadiazolyl, 1,3,4-oxadiazolyl or 1,3,4-thiadiazolyl, that is linked to the adjacent carbon atom by a ring carbon atom and optionally substituted by 1, 2 or 3 substituents each independently selected from methyl, benzyl, xcex1-(amino)benzyl, xcex1-(tert-butoxycarbonylamino)benzyl, benzylamino, benzylaminoethyl, aminomethylphenoxymethyl, methylaminomethylphenoxymethyl, dimethylaminomethylphenoxymethyl, pyrrolidinylmethylphenoxymethyl, aminoethoxybenzyl, phthalimidomethylphenoxymethyl, piperidyloxymethyl, benzylpiperidyloxymethyl, benzylpiperidyloxyethyl, morpholinomethyl, benzyloxycarbonylaminoethyl, amino, aminoethyl, R-xe2x88x9d-(amino)benzyl, S-xe2x88x9d-(amino)benzyl, pyrazinyl, benzyloxycarbonylpiperidinyloxymethyl, methylaminofuryl, cyclopropylmethylpiperidyloxymethyl, hydroxymethylphenoxymethyl, tertbutyloxycarbonylpiperazinylethyl, pyrimidinyl, benzylaminomethyl, (S)-xcex1-(benzyloxycarbonylamino)benzyl, piperazinoethyl, phenylcarbonylaminoethyl, dimethylaminomethyl, hydrogen, phenyl, cyclohexylamino or (R)-xcex1-(benzyloxycarbonylamino)benzyl.
More preferably still, R1 is
5-benzyl-1,2,4-oxadiazol-3-yl,
5-(4-[phthalimidomethyl]phenoxymethyl)-1,2,4-oxadiazol-3-yl,
5-(4-aminomethylphenoxymethyl-1,2,4-oxadiazol-3-yl,
5-(4-dimethylaminomethylphenoxymethyl)-1,2,4-oxadiazol-3-yl,
5-(4-pyrrolidinomethylphenoxymethyl)-1,2,4-oxadiazol-3-yl,
5-(4-methylaminomethylphenoxymethyl)-1,2,4-oxadiazol-3-yl,
5-(1-benzylpiperid-4-yloxymethyl)-1,2,4-oxadiazol-3-yl,
5-(xcex1-[tert-butoxycarbonylamino]benzyl)-1,2,4-oxadiazol-3-yl,
5-morpholinomethyl-1,2,4-oxadiazol-3-yl,
5-(2-[1-benzylpiperid-4-yloxy]ethyl)-1,2,4-oxadiazol-3-yl,
5-(1H-piperid-4-yloxymethyl)-1,2,4-oxadiazol-3-yl,
5-[xcex1-[amino]benzyl)-1,2,4-oxadiazol-3-yl,
5-(2-[benzyloxycarbonylamino]ethyl)-1,2,4-oxadiazol-3-yl,
5-(2-aminoethyl)-1,2,4-oxadiazol-3-yl,
5-(2-[benzylamino]ethyl)-1,2,4-oxadiazol-3-yl,
5-(4-[2-aminoethoxy]benzyl)-1,2,4-oxadiazol-3-yl,
5-methyl-1,3,4-thiadiazol-2-yl,
1H-1,2,4-triazol-3-yl,
1-benzyl-1H-1,2,4-triazol-3-yl,
5-benzyl-4-methyl-4H-1,2,4-triazol-3-yl,
5-amino-1,3,4-oxadiazol-2-yl,
5-benzylamino-1,3,4-oxadiazol-2-yl,
3-methylisoxazol-5-yl,
5-(pyrazin-2-yl)-1,2,4-oxodiazol-3-yl,
5-(R)-[xcex1-(amino)benzyl]-1,2,4-oxadiazol-3-yl,
5-(S)-[xcex1-(amino)benzyl]-1,2,4-oxadiazol-3-yl,
5-(5-methylaminofuran-2-yl)-1,2,4-oxadiazol-3-yl,
5-(1-benzyloxycarbonylpiperid-4-yloxymethyl)-1,2,4-oxadiazol-3-yl,
5-(1-cyclopropylmethylpiperid-4-yloxymethyl)-1,2,4-oxadiazol-3-yl,
5-(4-hydroxymethylphenoxymethyl)-1,2,4-oxadiazol-3-yl,
5-[2-(4-tert-butoxycarbonylpiperazin-4-yl)ethyl]-1,2,4-oxadiazol-3-yl,
5-(pyrimidin-2-yl)-1,2,4-oxadiazol-3-yl,
5-methyl-1,2,4-oxadiazol-3-yl,
5-benzylaminomethyl-1,2,4-oxadiazol-3-yl,
5-(S)-(xcex1-[benzyloxycarbonylamino]benzyl)-1,2,4-oxadiazol-3-yl,
5-(R)-(xcex1-[benzyloxycarbonylamino]benzyl)-1,2,4-oxadiazol-3-yl,
5-[2-(4H-piperazin-1-yl)ethyl]-1,2,4-oxadiazol-3-yl,
5-[2-(phenylcarbonylamino)ethyl]-1,2,4-oxadiazol-3-yl,
5-[2-(dimethylamino)ethyl]-1,2,4-oxadiazol-3-yl,
1,2,4-oxadiazol-3-yl,
5-phenyl-1,2,4-oxadiazol-3-yl,
2-benzyl-2H-1,2,3,4-tetraazol-5-yl,
5-benzyl-1,3,4-oxadiazol-2-yl,
5-[2-(phenyl)ethyl]-1,3,4-oxadiazol-2-yl,
5-methyl-2H-1,2,3,4-tetraazol-5-yl,
5-cyclohexylamino-1,3,4-oxadiazol-2-yl,
5-methyl-1,3,4-oxadiazol-2-yl,
3-methyl-1,2,4-oxadiazol-3-yl,
5-methyl-1,3-thiazol-2-yl,
5-methyl-1H-1,2,4-triazol-3-yl,
5aminomethyl-1,2,4-oxadiazol-3-yl or
2H-1,2,3,4-tetraazol-5-yl.
Most preferably R1 is
5-benzyl-1,2,4-oxadiazol-3-yl,
5-(4-[phthalimidomethyl]phenoxymethyl)-1,2,4-oxadiazol-3-yl,
5-(4-aminomethylphenoxymethyl)-1,2,4-oxadiazol-3-yl,
5-(4-dimethylaminomethylphenoxymethyl)-1,2,4-oxadiazol-3-yl,
5-(4-pyrrolidinomethylphenoxymethyl)-1,2,4-oxadiazol-3-yl,
5-(4-methylaminomethylphenoxymethyl)-1,2,4-oxadiazol-3-yl,
5-(1-benzylpiperid-4-yloxymethyl)-1,2,4-oxadiazol-3-yl,
5-(xcex1-[tert-butoxycarbonylamino]benzyl)-1,2,4-oxadiazol-3-yl,
5-(2-[1-benzylpiperid-4-yloxy]ethyl)-1,2,4-oxadiazol-3-yl,
5-(1H-piperid-4-yloxymethyl)-1,2,4-oxadiazol-3-yl,
5-[xcex1-[amino]benzyl)-1,2,4-oxadiazol-3-yl,
5-(2-[benzylamino]ethyl)-1,2,4-oxadiazol-3-yl,
5-(4-[2-aminoethoxy]benzyl)-1,2,4-oxadiazol-3-yl,
5-(pyrazin-2-yl)-1,2,4-oxodiazol-3-yl,
5-(R)-[xcex1-(amino)benzyl]-1,2,4-oxadiazol-3-yl,
5-(S)-[xcex1-(amino)benzyl]-1,2,4-oxadiazol-3-yl,
5-(5-methylaminofuran-2-yl)-1,2,4-oxadiazol-3-yl,
5-(1-benzyloxycarbonylpiperid-4-yloxymethyl)-1,2,4-oxadiazol-3-yl,
5-(1-cyclopropylmethylpiperid-4-yloxymethyl)-1,2,4-oxadiazol-3-yl,
5-(4-hydroxymethylphenoxymethyl)-1,2,4-oxadiazol-3-yl,
5-[2-(4-tert-butoxycarbonylpiperazin-4-yl)ethyl]-1,2,4-oxadiazol-3-yl,
5-(pyrimidin-2-yl)-1,2,4-oxadiazol-3-yl,
5-benzylaminomethyl-1,2,4-oxadiazol-3-yl,
5-(S)(xcex1-[benzyloxycarbonylamino]benzyl)-1,2,4-oxadiazol-3-yl or
5-[2-(4H-piperazin-1-yl)ethyl]-1,2,4-oxadiazol-3-yl.
Preferably, R2 is H, phenyl or C3-C7 cycloalkyl, said phenyl or cycloalkyl being optionally substituted by from 1 to 3 halo substituents, or R2 is a 5- or 6-membered ring heterocyclic group containing either 1 or 2 nitrogen heteroatoms or 1 oxygen heteroatom, said heterocyclic group being saturated or partially or fully unsaturated, optionally benzo-fused and optionally substituted, including in the benzo-fused portion, by from 1 to 3 C1-C6 alkyl, arylalkoxycarbonyl (e.g. benzyloxycarbonyl), halo or halo (C1-C6) alkyl, substituents,
said R2 group being attached to W by any mono- or bicyclic ring carbon atom or heteroatom.
More preferably, R2 is H, phenyl, cyclopentyl, cyclohexyl or cycloheptyl, said phenyl being optionally substituted by from 1 to 3 fluoro substituents, or R2 is imidazoly, pyrrolidinyl, piperidinyl or tetrahydrofuranyl, said imidazolyl or tetrahydrofuranyl group being optionally benzo-fused and optionally substituted, including in the benzo-fused portion, by from by from 1 to 3 methyl or bromine or fluorine substituents,
said R2 group being attached to W by any mono- or bicyclic ring carbon atom.
Yet more preferably, R2 is H, fluorophenyl, cyclohexyl, methylimidazolyl, benzimidazolyl, furanyl, cyclopentyl, cycloheptyl, bromobenzimidazolyl or fluorobenzimidazoyl.
Most preferably, R2 is H, 4-fluorophenyl, cyclohexyl, 1-methyl-1H-imidazol-4-yl, 1H-benzo[d]imidazol-2-yl, tetrahydrofuran-3-yl, cyclopentyl, cycloheptyl or 5-bromo-1H-benzo[d]imidazol-2-yl.
Preferably, W is a direct link or C1-C6 alkylene.
More preferably, W is a direct link, methylene, ethylene or 2,2-dimethyl-1,3-propylene. Most preferably, W is a direct link or methylene.
Preferably, Y is SO2 or xe2x80x94CONR5xe2x80x94.
Most preferably, Y is SO2 or xe2x80x94CONHxe2x80x94.
Preferred examples of xe2x80x94Yxe2x80x94Wxe2x80x94R2 include:
5-bromo1H-benzo[d]imidazol-2-ylsulphonyl,
1H-benzo[d]imidazol-2-ylsulphonyl,
1-methyl-1H-imidazol4-ylsulphonyl,
tetrahydrofuran-3-ylmethylsulphonyl,
cyclohexylmethylsulphonyl,
4-fluorophenylsulphonyl,
N-(2,2-dimethylprop-1-yl)aminocarbonyl,
cyclopentylmethyl sulphonyl,
cycloheptylmethyl sulphonyl,
1-(benzyloxycarbonyl)pyrrolidin-3-ylmethylsulphonyl,
1-(benzyloxycarbonyl)piperid-3-ylmethylsulphonyl,
benzylaminocarbonyl or
phenethylaminocarbonyl.
Highly preferred examples of xe2x80x94Yxe2x80x94Wxe2x80x94R2 include:
5-bromo1H-benzo[d]imidazol-2-ylsulphonyl,
1H-benzo[d]imidazol-2-ylsulphonyl,
cyclohexylmethylsulphonyl,
4-fluorophenylsulphonyl,
cyclopentylmethyl sulphonyl or
cycloheptylmethyl sulphonyl.
Preferably, A is unbranched C3-C4 alkylene (i.e. 1,3-propylene or 1,4-butylene). Most preferably A is C4 alkylene.
In a preferred embodiment of the present invention R1 is 1,2,4 or 1,3,4 oxadiazole, that is linked to the adjacent carbon atom by a ring carbon atom which is optionally preferably-mono-substituted by one of xe2x80x94X-aryl or xe2x80x94X-het wherein X is preferably selected from xe2x80x94(C0-C2 alkylene)xe2x80x94Zxe2x80x94(C0-C2 alkylene), more preferably xe2x80x94(C1 alkylene)xe2x80x94Zxe2x80x94(C0 alkylene) where Z is xe2x80x94Oxe2x80x94; or X is a direct link or xe2x80x94(C1-C2 alkylene); or X is xe2x80x94(C0 alkylene)xe2x80x94Zxe2x80x94(C0 alkylene) where Z is xe2x80x94CR5NR3R4, or xe2x80x94CR5NR5(CO2R5) where R3 and R4 are selected from H, xe2x80x94(C1-C3 alkylene), more preferably H, xe2x80x94(C1-C2 alkylene) and R5 is H or xe2x80x94(C1-C4 alkylene), or xe2x80x94(C1-C2 alkylene)aryl; or X is xe2x80x94(C1-C2 alkylene)xe2x80x94Zxe2x80x94(C1-C2 alkylene)(aryl) where Z is NR5 and R5 is H or xe2x80x94(C1-C2 alkylene)-;
wherein aryl of xe2x80x94X-aryl is phenyl optionally substituted by from 1 to 3 substituents independently selected from xe2x80x94(C1-C3 alkylene) NR3 R4, xe2x80x94(C1-C6 alkylene)(phthalimido); xe2x80x94O(C1-C3 alkylene) NR3R4 or xe2x80x94C02R5 wherein R3 and R4 are each independently selected from H, C1-C3 alkyl or, when taken together, represent unbranched C3-C5 alkylene; and R5 is H, C1-C4 alkyl or xe2x80x94(C1-C2 alkylene)aryl;
wherein xe2x80x9chetxe2x80x9d of xe2x80x94X-het is piperidinyl, furyl, pyrazinyl, pyrimidinyl or piperazinyl optionally substituted by xe2x80x94(C1-C3 alkylene)(xe2x80x94C3-C6 cycloalkyl), xe2x80x94CO2R5, xe2x80x94(C1-C3 alkylene)NR3R4 or xe2x80x94(C1-C2 alkylene)aryl wherein aryl is phenyl and wherein R3 and R4 are selected from H, xe2x80x94(C1-C3 alkylene), more preferably H, xe2x80x94(C1-C2 alkylene) and R5 is H or xe2x80x94(C1-C4 alkylene), or xe2x80x94(C1-C2 alkylene)aryl;
or X is xe2x80x94(C1-C2 alkylene)xe2x80x94Zxe2x80x94(C1-C2 alkylene)(aryl) where Z is NR5 and R5 is H or xe2x80x94(C1-C2 alkylene)xe2x80x94.
Further preferred embodiments of the present invention are as follows:
1H-Benzo[d]imidzol-2-yl[2S]-2-(5-benzyl-1,2,4-oxadiazol-3-yl)-1-piperidylsulphone, 2-[4-(3-[(2S)-1-(1H-Benzo[d]imidazol-2-ylsulfonyl)piperidyl-1,2,4-oxadiazol-5-ylmethoxy)benzyl]-1,3-isoindolinedione, 4-(3-[(2S)-1-(1H-Benzo[d]imidazol-2-ylsulfonyl)-2-piperidyl]-1,2,4-oxadiazol-5-ylmethoxy)benzylamine, N-[4-(3-[(2S)-1-(1H-Benzo[d]imidazol-2-ylsulfonyl)-2-piperidyl]-1,2,4-oxadiazol-5-ylmethoxy)benzyl]-N,N-dimethylamine, 3-[1-(1H-Benzo[d]imidazol-2-ylsulfonyl)-2-piperidyl]-5-[4-(1-pyrrolidylmethyl)phenoxy]methyl-1,2,4-oxadiazole, N-[4-(3-[1-(1H-Benzo[d]imidazol-2-ylsulfonyl)-2-piperidyl]-1,2,4-oxadiazol-5-ylmethoxy)benzyl]-N-methylamine, 4-[3-((2S)-1-[Cyclohexylmethylsulfonyl]-2-piperidyl)-1,2,4-oxadiazol-5-ylmethoxy]benzylamine, 5-[(1-Benzyl-4-piperidyl)oxymethyl]-3-[(2S)-1-cyclohexylmethylsulfonyl-2-piperidyl]-1,2,4-oxadiazole, 3-[(2S)-1-Cyclohexylmethylsulfonyl-2-piperidyl]-5-[4-piperidyloxymethyl]-1,2,4-oxadiazole, (3-[(2S)-1-Cyclohexylmethylsulfonyl-2-piperidyl]-1,2,4-oxadiazol-5-yl)(phenyl)methylamine, 5-(3-(2S)-1-[(Cyclohexylmethyl)sulfonyl]-2-piperidyl-1,2,4-oxadiazol-5-yl)-2-furyl]methylamine, N-(2-(3-[1-(1H-Benzo[d]imidazol-2-ylsulfonyl)-2-piperidyl]-1,2,4-oxadiazol-5-yl)ethyl)benzylamine, 2-[4-(3-[1-(1H-Benzo[d]imidazol-2-ylsulfonyl)-2-piperidyl]-1,2,4-oxadiazol-5-ylmethyl)phenoxy]ethylamine, N-(3-[1-(1H-benzo[d]imidazol-2-ylsulfonyl)-2-piperidyl]-1,2,4-oxadiazol-5-ylmethyl)-N-benzylamine, 2-[(2S)-2-5-[(4-Piperidyloxy)methyl]-1,2,4-oxadiazol-3-yl-1-piperidyl]sulfonyl-1H-benzo[d]imidazole, 2-[(2S)-2-[5-([1-(Cyclopropylmethyl)-4-piperidyl]oxymethyl)-1,2,4-oxadiazol-3-yl]-1-piperidyl]sulfonyl-1H-benzo[d]imidazole, 2-[(2S)-2-(5-Benzyl-1,2,4-oxadiazol-3-yl)-1-piperidyl]sulfonyl-5-bromo-1H-benzo[d]imidazole, 2-4-[(3-(2S)-1-[(5-Bromo-1H-benzo[d]imidazol-2-yl)sulfonyl]-2-piperidyl-1,2,4-oxadiazol-5-yl)methoxy]benzyl-1,3-isoindolinedione, 4-[(3-(2S)-1-[(5-Bromo-1H-benzo[d]imidazol-2-yl)sulfonyl]-2-piperidyl-1,2,4-oxadiazol-5-yl)methoxy]benzylamine, tert-Butyl 4-[2-(3-(1S)-2-[(cyclohexylmethyl)sulfonyl]-2-piperidyl-1,2,4-oxadiazol-5-yl)ethyl]-1-piperazinecarboxylate, (R)-(3-{(2S)-1-[(Cyclohexylmethyl)sulfonyl]-2-piperidyl}-1,2,4-oxadiazol-5-yl)(phenyl)methylamine, (S)-(3-{(2S)-1-[(Cyclohexylmethyl)sulfonyl]-2-piperidyl}-1,2,4-oxadiazol-5-yl)(phenyl)methylamine, 2-({2-[5-(2-pyrimidinyl)-1,2,4-oxadiazol-3-yl]-2-piperidyl}sulfonyl)-1H-benzo[d]imidazole, Benzyl 4-(3-[(2S)-1-(1H-benzo[d]imidazol-2-ylsulfonyl)-2-piperidyl]-1,2,4-oxadiazol-5-ylmethoxy)-1-piperidinecarboxylate, (2S)-2-(5-Benzyl-1,2,4-oxadiazol-3-yl)-1-[(cyclopentylmethyl)sulphonyl]piperidine, (2S)-2-(5-Benzyl-1,2,4-oxadiazol-3-yl)-1-[(cyclohexylmethyl)sulphonyl]piperidine, (2S)-2-(5-Benzyl-1,2,4-oxadiazol-3-yl)-1-[(cycloheptylmethyl)sulphonyl]piperidine, tert-Butyl-N-(3-{(2S)-1-(cyclohexylmethyl)sulphonyl-2-piperidyl}-1,2,4-oxadiazol 5-yl)(phenyl)methylcarbamate, (2S)-2-(5-{2-[(1-Benzyl-4-piperidyl)oxy]ethyl}-1,2,4-oxadiazol-3-yl)-1-(cyclohexylmethyl)sulphonyl]piperidine, {4-{3-{2S-1-[4-Fluorophenyl)sulphonyl]piperidyl}-1,2,4-oxadiazol-5-yl)methoxy]phenyll}methanol, 2-(3-{(2S)-1-[4-Fluorophenyl)sulphonyl]piperidyl}-1,2,4-oxadiazol-5-yl)pyrazine or 1-[2-(3-(1S)-2-[(Cyclohexylmethyl)sulphonyl]-2-piperidyl-1,2,4-oxadiazol-5-yl)ethyl]piperazine.
According to a further aspect of the invention there are provided compounds of formula (I) as defined herein before but wherein the optional substituent on R2, where R2 is a 5-, 6-, or 7-membered ring heterocyclic group, is not, CO2R5; or wherein the optional substituent on the xe2x80x9carylxe2x80x9d group of xe2x80x94X-aryl or R5 is not xe2x80x94(C1-C6 alkylene)OH; or wherein the optional substituent on the xe2x80x94X-het group is not C3-C7 cycloalkyl or xe2x80x94(C1-C6 alkylene)(C3-C7 cycloalkyl).
Particularly preferred examples of the compounds of the formula (I) are as described in the Examples section hereafter.
The compounds of the formula (I) can be prepared using conventional procedures such as by the following illustrative methods.
1. All the compounds of the formula (I) can be prepared by
(a) reaction of a compound of the formula: 
xe2x80x83wherein R1 and A are as previously defined for a compound of the formula (I), with a compound of the formula:
L1xe2x80x94Yxe2x80x94Wxe2x80x94R2xe2x80x83xe2x80x83(III)
xe2x80x83wherein R2, W and Y are as previously defined for a compound of the formula (I) and L1 is a suitable leaving group, e.g. fluoro, chloro or bromo; or
(b) by ring formation or ring closure of a corresponding open ring structure, to formula (II), wherein the said open ring corresponds to an optionally substituted heterocycle R1 followed by reaction with a compound of formula (III) as detailed herein before; or
(c) by ring formation or ring closure of a corresponding open ring structure, to formula (I), wherein the said open ring corresponds to an optionally substituted heterocycle R1.
If an acid addition salt of a compound of the formula (II) is used as the starting material, this may be converted to the free base in situ using a suitable acid acceptor, e.g. ethyldiisopropylamine.
For all definitions of Y, L1 may be chloro and the reaction can be carried out in the presence of a suitable additional acid acceptor, e.g. ethyldiisopropylamine or triethylamine, and in a suitable solvent, e.g. dichloromethane. Where Y is SO2, L1 may be fluoro and the reaction can be carried out under similar conditions.
Where Y is carbonyl, xe2x80x94CONR5xe2x80x94, xe2x80x94CO.COxe2x80x94, xe2x80x94CO.CSxe2x80x94 or xe2x80x94CO.CH(OH)xe2x80x94, L1 may also be a group that forms an activated derivative of a carboxylic acid, e.g. an activated ester or imidazol-1-yl. The reaction may be carried out under conventional conditions.
The intermediate compounds of the formula (II) may be prepared by conventional methods, for example, where the heteroaryl group of R1 is a 1,2,4-oxadiazol-3-yl group, by the route shown in Scheme 1. 
wherein A is as previously defined for a compound of the formula (I) and R1A is a relevant group corresponding to an optional substituent on the heteroaryl group as previously defined for R1 for a compound of the formula (I).
A salt of the formula (IIA) is usually used directly in the reaction with a compound of the formula (III) where it may be converted to the corresponding free base of the formula (II) in situ using a suitable acid acceptor, e.g. ethyldiisopropylamine.
The intermediate compounds of the formula (III) may be prepared by conventional methods.
2. The compounds of the formula (I) wherein Y is xe2x80x94CONHxe2x80x94 and R1, R2, A and W are as previously defined for a compound of the formula (I) can be prepared by reaction of a compound of the formula (II) wherein R1 and A are as previously defined for a compound of the formula (I), with an isocyanate of the formula:
R2xe2x80x94Wxe2x80x94NCOxe2x80x83xe2x80x83(XI)
wherein R2 and W are as previously defined for a compound of the formula (I).
The reaction may be carried out in a suitable solvent, e.g. dichloromethane.
The intermediate compounds of the formula (XI) can be prepared by conventional methods.
3. The compounds of the formula (I) wherein Y is xe2x80x94CONR5xe2x80x94 and R1, R2, R5, A and W are as previously defined for a compound of the formula (I) can be prepared by reaction of a compound of the formula (II) wherein R1 and A are as previously defined for a compound of the formula (I), first with a suitable carbonylation reagent, e.g. phosgene [or an equivalent thereof (e.g. triphosgene)] or 1,1xe2x80x2-carbonyldiimidazole, and then with a compound of the formula:
R2xe2x80x94Wxe2x80x94NHR5xe2x80x83xe2x80x83(XII)
wherein R2, R5 and W are as previously defined for a compound of the formula (I), the reaction being optionally carried out in the presence of a suitable acid acceptor, e.g. triethylamine.
The reaction may be carried out in a suitable solvent, e.g. dichloromethane.
The intermediate amines of the formula (XII) can be prepared by conventional methods.
4. The compounds of the formula (I) wherein R1 is an optionally substituted 1,2,4-oxadiazol-3-yl heteroaryl group and R2, A, W and Y are as previously defined for a compound of the formula (I) can be prepared by ring closure of a compound of the formula: 
wherein R2, A, W and Y are as previously defined for a compound of the formula (I) and R1A is a relevant group corresponding to an optional substituent on the heteroaryl group as previously defined for R1 for a compound of the formula (I).
The reaction may be carried out in a suitable solvent, e.g. xylene or pyridine, and at the reflux temperature thereof.
The intermediate compounds of the formula (XIIA) can be prepared by a similar method to that used to prepare a compound of the formula (IX) in Scheme 1 by initially converting a compound of the formula (IV) to a compound of the formula: 
wherein R2, A, W and Y are as previously defined for a compound of the formula (I), using a conventional method, and then by following the route indicated therein.
5. The compounds of the formula (I) wherein R1 is an optionally substituted 1,3,4-oxadiazolyl heteroaryl group and R2, A, W and Y are as previously
6. defined for a compound of the formula (I) can be prepared by ring closure of a compound of the formula: 
wherein R2, A, W and Y are as previously defined for a compound of the formula (I) and R1A is a relevant group corresponding to an optional substituent on the heteroaryl group as previously defined for R1 for a compound of the formula (I).
The reaction may be carried out under suitable conditions such as using a mixture of triphenylphosphine, iodine and triethylamine in dichloromethane. A compound of the formula (XIV) can be prepared by reaction of a compound of the formula (XIII) with a compound of the formula:
R1ACONHNH2xe2x80x83xe2x80x83(XV)
under conventional dehydration conditions.
6. The compounds of the formula (I) wherein R1 is a 1,3,4-oxadiazolyl heteroaryl group bearing an optionally substituted amino substituent (R1B) (as previously defined for R1) and R2, A, W and Y are as previously defined for a compound of the formula (I) can be prepared by ring closure of a compound of the formula: 
wherein R2, A, W and Y are as previously defined for a compound of the formula (I) and R1B is a relevant optionally substituted amino substituent as defined above.
The reaction may be carried out using mercuric oxide in 1,4-dioxane and at the reflux temperature.
A compound of the formula (XVI) can be prepared by reaction of a compound of the formula (XIII) first with a carboxyl group activating reagent (e.g. 1,1xe2x80x2-carbonyldiimidazole) followed by a compound of the formula:
R1BCSNHNH2xe2x80x83xe2x80x83(XVII)
wherein R1B is as previously defined for this method, under conventional conditions.
7. The compounds of the formula (I) wherein R1 is an optionally substituted 1,3,4-thiadiazolyl heteroaryl group and R2, A, W and Y are as previously defined for a compound of the formula (I) can be prepared by reaction of a compound of the formula (XIV) wherein R2, A, W, Y and R1A are as previously defined for a compound of the formula (XIV) with a thionating agent, e.g. P4S10 or Lawesson""s reagent (2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulphide) in a suitable solvent, e.g. toluene, preferably at the reflux temperature thereof.
8. The compounds of the formula (I) wherein R1 is an optionally substituted 1,2,4-triazol-3-yl heteroaryl group and R2, A, W and Y are as previously defined for a compound of the formula (I) can be prepared by reaction of a compound of the formula: 
where R2, A, W and Y are as previously defined for a compound of the formula (I) and R10 is C1-C4 alkyl, e.g. methyl or ethyl, with a compound of the formula:
R1ANHNHCHOxe2x80x83xe2x80x83(XIX)
wherein R1A is a relevant group corresponding to an optional substituent on the heteroaryl group as previously defined for R1 for a compound of the formula (I).
The reaction may be carried out in a suitable solvent such as a mixture of toluene and 1,4-dioxane, and at the reflux temperature thereof. A compound of the formula (XVIII) can be prepared by reaction of a compound of the formula: 
wherein R2, A, Y and W are as previously defined for a compound of the formula (I), with a tri(C1-C4 alkyl)oxonium hexafluorophosphate in dichloromethane.
A compound of the formula (XX) can be prepared as described in Method (4) above or by treatment of a compound of the formula (XXIV) with ammonia.
9. The compounds of the formula: 
wherein R2, A, W and Y are as previously defined for a compound of the formula (I) and R1C is relevant group corresponding to a substituent on the heteroaryl group as previously defined for R1 for a compound of the formula (I) that is linked to the ring nitrogen atom by a methylene group, can be prepared by alkylation of a compound of the formula: 
wherein R2, A, W and Y are as previously defined for a compound of the formula (I) (a compound of the formula (IB) is prepared by the route described in Method (8) above, i.e. where R1A is H) using an appropriate alkylating agent and under conventional conditions. Regioisomers may be formed in this reaction and they may be separated by chromatography.
10. The compounds of the formula (I) wherein R1 is an optionally substituted 4-(C1-C6 alkyl)-4H-1,2,4-triazol-3-yl heteroaryl group and R2, A, W and Y are as previously defined for a compound of the formula (I) can be prepared by reaction of a compound of the formula: 
wherein R2, A, W and Y are as previously defined for a compound of the formula (I), with a compound of the formula (XV) wherein R1A is as previously defined for a compound of the formula (XV), in the presence of mercuric oxide.
The reaction may be carried out in a suitable solvent, e.g. 1,4-dioxane or dimethylacetamide, and at the reflux temperature.
A compound of the formula (XXI) can be prepared under conventional conditions as shown in Scheme 2. 
wherein R2, A, W and Y are as previously defined for a compound of the formula (I).
11. The compounds of the formula (I) wherein R1 is an optionally 3-substituted isoxazol-5-yl heteroaryl group and R2, A, W and Y are as previously defined for a compound of the formula (I) can be prepared by ring closure of a compound of the formula: 
wherein R2, A, W and Y are as previously defined for a compound of the formula (I) and R1A is a relevant group corresponding to an optional substituent on the heteroaryl group as previously defined for R1 for a compound of the formula (I).
The reaction may be carried out using mesyl chloride, triethylamine and dichloromethane as the solvent.
A compound of the formula (XXIII) can be prepared as shown in Scheme 3. 
wherein R2, A, W, Y and R1A are as previously defined for this method.
12. The compounds of the formula (I) wherein R1 is an optionally substituted 1,2,3,4-tetraazol-5-yl heteroaryl group and R2, A, W and Y are as previously defined for a compound of the formula (I) can be prepared by known methods such as, for example, by reaction of a compound of the formula (XXV): 
where R2, A, W and Y are as previously defined for a compound of the formula (I) with trimethylsilyl azide and dibutyltin oxide. The reaction may be carried out in a suitable solvent such as toluene and at the reflux temperature thereof. Compounds such as formula (XXV) can be N-alkylated using an appropriate alkylating agent and under conventional conditions regioisomers may be formed which can be separated be standard chromatogaphical methods.
13. The compounds of the formula (I) wherein R1 is an optionally substituted 1,2,4-oxadiazol-5-yl heteroaryl group and R2, A, W and Y are as previously defined for a compound of the formula (I) can be prepared by standard methods such as for example, by heat treatment of a compound of the formula (XXVI): 
where R2, A, W and Y are as previously defined for a compound of the formula (I), in a suitable solvent such as xylene at reflux temperature. The compound of the formula (XXVI) can be prepared by reacting a compound of the formula (XIII) with a N1-hydroxyimidamide, such as N1-hydroxyethanimidamide. Suitable reaction conditions would be for example, in the presence of hydroxybenzotriazole hydrate, N-methyl morpholine, and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, in a solvent such as dichloromethane, at room temperature.
14. It will be appreciated that certain compounds of the formula (I) can be converted to other compounds of the formula (I) by conventional methods, e.g. using standard functional group interconversion techniques.
All of the above reactions and the preparations of novel starting materials using in the preceding methods are conventional and appropriate reagents and reaction conditions for their performance or preparation as well as procedures for isolating the desired products will be well-known to those skilled in the art with reference to literature precedents and the Examples and Preparations hereto.
A pharmaceutically acceptable salt of a compound of the formula (I) may be readily prepared by mixing together solutions of a compound of the formula (I) and the desired acid or base, as appropriate. The salt may precipitate from solution and be collected by filtration or may be recovered by evaporation of the solvent.
The affinity of the compounds of the formula (I) for FKBP-12 can be determined in vitro in a coupled colorimetric PPlase assay using similar procedures to published methods (e.g. see Kofron, J. L., et al., Biochemistry, 1991, 30, 6127-6134, Zarnt, T., et al., Biochem. J. 1995, 305, 159-164, Holt, D. A., et al., J. Am. Chem. Soc., 1993,115, 9925-9938). In these methods, the cis-trans isomerisation of a hydrophobic amino acid-proline bond in a tetrapeptide substrate (e.g. the phenylalanine-proline bond in N-succinyl-ala-phepro-phe-p-nitroanilide [succinyl-AFPF-pNA]) can be determined by monitoring cleavage of pNA from the transPro-containing peptide by an excess of chymotrypsin.
The IC50 (the concentration of the compound of the formula (I) producing 50% inhibition) values were determined using the following assay methodology. Assay buffer (2.175 ml) (50 mM 4-(2-hydroxyethyl)-1-piperazineethanesulphonic acid (HEPES), 100 mM NaCl, 1 mM dithiothreitol (DTT), pH 8.0) is equilibrated to 10xc2x0 C. in a cuvette. 12.5 xcexcl of a solution of the present compound in DMSO, 250 xcexcl of a 60 mg/ml solution of a-chymotrypsin in 1 mM aqueous hydrochloric acid and then 50 xcexcl of a solution of human recombinant FKBP-12 (4.5 xcexcM) in assay buffer are added and mixed. The reaction is initiated by addition of 12.5 xcexcl of a solution of 20 mM succinyl-AFPF-pNA in DMSO. The absorbance at 390 nM is monitored for one minute collecting data every 0.25 second. Data are fitted with a first order rate equation with offset and the rate constant obtained corrected for the rate of uncatalysed isomerisation of the substrate. The rate constant determined at different inhibitor concentrations (10 nM to 100 xcexcM) is expressed as % inhibition of the control rate constant. The IC50 is estimated using a nonlinear least squares curve fitting routine of the sigmoidal dose response data.
Ki,app (the apparent inhibition constant) was determined for the present compounds using the assay procedure described below. Assay buffer (2.175 ml) (50 mM HEPES, 100 mM NaCl, 1 mM DTT, pH 8.0) is equilibrated to 10xc2x0 C. in a cuvette. 12.5 xcexcl of a solution of the present compound in DMSO, 250 xcexcl of a 60 mg/ml solution of xcex1-chymotrypsin in 1 mM aqueous hydrochloric acid and then 50 xcexcL of a solution of human recombinant FKBP-12 (1.5 xcexcM) in assay buffer are added and mixed. The reaction is initiated by adding 12.5 xcexcl of a solution of anhydrous succinyl-ALPF-pNA (100 xcexcM final concentration) in a 400 mM solution of LiCl in trifluoroethanol. The absorbance at 390 nM is monitored for 3 minutes collecting data every 0.5 second. Data are fitted with a first order rate equation with offset and the initial velocity (v) is calculated from the concentration of cis (re leu-pro bond)succinyl-ALPF-pNA at t0 and the first order rate constant at different inhibitor concentrations (I). Data in the form vinh/vcontrol v. [I] are fitted with an equation for reversible tight binding inhibition to generate values for Ki,app (see Morrison, J. F., et al, Comments Mol. Cell Biophys., 1985, 2, 347-368). This analysis is used when the Ki,app approaches the concentration of FKBP-12 in the assay (30 nM). Dixon analysis (see Dixon, M., Biochem. J.,1953, 55, 170-171) is used for generating values of Ki,app for less potent compounds.
The same methodology is used to generate Ki,app for FKBP52 with the following modifications: Forty microliters human recombinant FKBP52 (5.2 xcexcM) is substituted for FKBP12 and 2.185 ml assay buffer are used in the assay.
The compounds of the invention have inhibitory activity against the FKBP-12 enzyme. Early experimentation suggests that the compounds of the invention also have inhibitory activity against the FKPB-52 enzyme.
The neurite outgrowth promoting activity of the compounds of the formula (I) can be determined in explant cultures of embryonic chick dorsal root ganglia. Dorsal root ganglia (DRG) are isolated aseptically according to the method of Bray (see xe2x80x9cCulturing Nerve Cellsxe2x80x9d, Ed. G. Banker and K. Goslin, MIT Press, Cambridge, Mass., 1991, p.119). The individual ganglia were kept in Ca2+/Mg2+-free Tyrodes buffer on ice until a number of ganglia had been collected. Individual ganglia were then transferred into collagen-coated 24-well culture plates containing Neurobasal medium plus B27 supplements and incubated at 37xc2x0 C. in a 5% CO2 atmosphere. The present compound was added after allowing 4 hours for the ganglia to attach. The explants were fixed and stained with Coomassie blue after 24 or 48 hours in culture. For each treatment 4 to 6 ganglia were analysed and scored by estimating the extent of neurite outgrowth relative to the diameter of the explant using image analysis. The present compounds were tested with and without 10 ng/ml nerve growth factor (NGF) present and compared to outgrowth in the presence of 10 ng/ml nerve growth factor alone.
An alternative system for measuring neurite outgrowth promoting activity of FKBP-12 PPlase inhibitors is the SH-SY-5Y neuroblastoma model described by Gold, B. G., et al, in Exp. Neurol., 1997, 147(2), 269-278. Cells are maintained in Dulbecco""s Modified Eagle""s Medium (DMEM) supplemented with 10% Fetal calf serum (FCS), 50 U/ml penicillin, 50 xcexcg/ml streptomycin at 37xc2x0 C. in a 7% CO2 atmosphere. Cells are plated at 1xc3x97106 cells per well and treated for 5 days with 400 nM aphidicolin. Cells are then washed and treated with NGF at 10 ng/mlxc2x1various compound concentrations for 7 days to determine if the compounds promote neurite outgrowth in the presence of suboptimal NGF concentrations (and/or in the absence of NGF). Neurite outgrowth is determined by using image analysis to measure neurite lengths in 20 random fields.
The neurotrophic activity of the present compounds can be evaluated in vivo using the sciatic nerve crush model in rat as a model for peripheral nerve regeneration (see Bridge, P. M., et al. , Experimental Neurology, 1994, 127, 284-290, Medinaceli, L., et al., Expl. Neurology, 1982, 77, 634-643, Gold, B. G.,et al., Restorative Neurology and Neuroscience, 1994, 6, 287-296), the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 6-hydroxydopamine models in various species as a model for regeneration in Parkinson""s disease (see Mokry, J., Physiol. Res., 1995, 44(3), 143-150) and fimbria-fornix lesions as a model for regeneration in Alzheimer""s disease (see Cassel, J. C., Duconseille, E., Jeltsch, H. and Will, B., Prog. Neurol., 1997, 51, 663-716).
The compounds of the formula (I) can be administered alone but will generally be administered in admixture with a suitable pharmaceutical excipient diluent or carrier selected with regard to the intended route of administration and standard pharmaceutical practice.
For example, the compounds of the formula (I) can be administered orally or sublingually in the form of tablets, capsules, ovules, elixirs, solutions or suspensions, which may contain flavouring or colouring agents, for immediate or controlled release applications.
Such tablets may contain excipients such as microcrystalline cellulose, lactose, sodium citrate, calcium carbonate, dicalcium phosphate and glycine, disintegrants such as starch (preferably corn, potato or tapioca starch), alginic acid and certain complex silicates, and granulation binders such as polyvinylpyrrolidone, sucrose, gelatin and acacia. Additionally, lubricating agents such as magnesium stearate, sodium lauryl sulfate and talc may be included.
Solid compositions of a similar type may also be employed as fillers in gelatin capsules. Preferred excipients in this regard include lactose or milk sugar as well as high molecular weight polyethylene glycols. For aqueous suspensions and/or elixirs, the compounds of the formula (I) may be combined with various sweetening or flavouring agents, colouring matter or dyes, with emulsifying and/or suspending agents and with diluents such as water, ethanol, propylene glycol and glycerin, and combinations thereof.
The compounds of the formula (I) can also be injected parenterally, for example, intravenously, intraperitoneally, intrathecally, intraventricularly, intrasternally, intracranially, intramuscularly or subcutaneously, or they may be administered by infusion techniques. They are best used in the form of a sterile aqueous solution which may contain other substances, for example, enough salts or glucose to make the solution isotonic with blood. The aqueous solutions should be suitably buffered (preferably to a pH of from 3 to 9), if necessary. The preparation of suitable parenteral formulations under sterile conditions is readily accomplished by standard pharmaceutical techniques well-known to those skilled in the art.
For oral and parenteral administration to human patients, the daily dosage level of the compounds of the formula (I) will usually be from 1 microgram/kg to 25 mg/kg (in single or divided doses).
Thus tablets or capsules of the compound of the formula (I) may contain from 0.05 mg to 1.0 g of active compound for administration singly or two or more at a time, as appropriate. The physician in any event will determine the actual dosage which will be most suitable for any individual patient and it will vary with the age, weight and response of the particular patient. The above dosages are exemplary of the average case. There can, of course, be individual instances where higher or lower dosage ranges are merited and such are within the scope of this invention.
The compounds of formula (I) can also be administered intranasally or by inhalation and are conveniently delivered in the form of a dry powder inhaler or an aerosol spray presentation from a pressurised container or a nebuliser with the use of a suitable propellant, e.g. dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, a hydrofluoroalkane such as 1,1,1,2-tetrafluoroethane (HFA 134A [trade mark] or 1,1,1,2,3,3,3-heptafluoropropane (HFA 227EA [trade mark]), carbon dioxide or other suitable gas. In the case of a pressurised aerosol, the dosage unit may be determined by providing a valve to deliver a metered amount. The pressurised container or nebuliser may contain a solution or suspension of the active compound, e.g. using a mixture of ethanol and the propellant as the solvent, which may additionally contain a lubricant, e.g. sorbitan trioleate. Capsules and cartridges (made, for example, from gelatin) for use in an inhaler or insufflator may be formulated to contain a powder mix of a compound of the formula (I) and a suitable powder base such as lactose or starch.
Aerosol or dry powder formulations are preferably arranged so that each metered dose or xe2x80x9cpuffxe2x80x9d contains from 20 xcexcg to 20 mg of a compound of the formula (I) for delivery to the patient. The overall daily dose with an aerosol will be in the range of from 20 xcexcg to 20 mg which may be administered in a single dose or, more usually, in divided doses throughout the day.
Alternatively, the compounds of the formula (I) can be administered in the form of a suppository or pessary, or they may be applied topically in the form of a lotion, solution, cream, ointment or dusting powder. The compounds of the formula (I) may also be transdermally administered by the use of a skin patch. They may also be administered by the ocular route, particularly for treating neurological disorders of the eye.
For ophthalmic use, the compounds can be formulated as micronised suspensions in isotonic, pH adjusted, sterile saline, or, preferably, as solutions in isotonic, pH adjusted, sterile saline, optionally in combination with a preservative such as a benzylalkonium chloride. Alternatively, they may be formulated in an ointment such as petrolatum.
For application topically to the skin, the compounds of the formula (I) can be formulated as a suitable ointment containing the active compound suspended or dissolved in, for example, a mixture with one or more of the following: mineral oil, liquid petrolatum, white petrolatum, propylene glycol, polyoxyethylene polyoxypropylene compound, emulsifying wax and water. Alternatively, they can be formulated as a suitable lotion or cream, suspended or dissolved in, for example, a mixture of one or more of the following: mineral oil, sorbitan monostearate, a polyethylene glycol, liquid paraffin, polysorbate 60, cetyl esters wax, cetearyl alcohol, 2-octyldodecanol, benzyl alcohol and water.
The compounds of the formula (I) can also be administered together with other neutrophic agents such as neurotrophic growth factor (NGF), glial derived growth factor, brain derived growth factor, ciliary neurotrophic factor and/or neurotrophin-3. The dosage level of the neurotrophic agent will depend upon the neurotrophic effectiveness of the combination and the route of administration used.
It is to be appreciated that all references herein to treatment include curative, palliative and prophylactic treatment.
Thus the invention further provides:
(i) a pharmaceutical composition comprising a compound of the formula (I) or a pharmaceutically acceptable salt or solvate thereof, together with a pharmaceutically acceptable excipient, diluent or carrier,
(ii) a compound of the formula (I) or a pharmaceutically acceptable salt, solvate or composition thereof, for use as a medicament;
(iii) the use of a compound of the formula (I) or of a pharmaceutically acceptable salt, solvate or composition thereof, for the manufacture of a medicament for the treatment of neuronal degeneration;
(iv) the use of a compound of the formula (I) or of a pharmaceutically acceptable salt, solvate or composition thereof, for the manufacture of a medicament for the promotion of neuronal regeneration and outgrowth;
(v) the use of a compound of the formula (I) or of a pharmaceutically acceptable salt, solvate or composition thereof, for the manufacture of a medicament for the treatment of a neurological disease or disorder such as a neurodegenerative disease;
(vi) use as in (v) where the neurological disease or disorder is selected from the group consisting of senile dementia (Alzheimer""s disease) and other dementias, amyotrophic lateral sclerosis and other forms of motor neuron disease, Parkinson""s disease, Huntington""s disease, neurological deficits associated with stroke, all forms of degenerative disease affecting the central or peripheral nervous system (e.g. cerebellar-brainstem atrophies, syndromes of progressive ataxias), all forms of muscular dystrophy, progressive muscular atrophies, progressive bulbar muscular atrophy, physical or traumatic damage to the central or peripheral nervous system (e.g. spinal cord), herniated, ruptured or prolapsed intervertebrae disc syndromes, cervical spondylosis, plexus disorders, thoracic outlet syndromes, all forms of peripheral neuropathy (both diabetic and non-diabetic), trigeminal neuralgia, glossopharyngeal neuralgia, Bell""s Palsy, all forms of auto-immune related disease resulting in damage of the central or peripheral nervous system (e.g. multiple sclerosis, myasthenia gravis, Guillain-Barrxc3xa9 syndrome), AIDS related disorders of the nervous system, dapsone ticks, bulbar and retrobulbar affections of the optic nerve (e.g. retinopathies and retrobulbar neuritis), hearing disorders such as tinnitus, and prion diseases;
vii) use as (vi) where the neurological disease or disorder is senile dementia (Alzheimer""s disease) or another dementia, amyotrophic lateral sclerosis or another form of motor neuron disease, Parkinson""s disease, Huntington""s disease, a neurological deficit associated with stroke, physical or traumatic damage to the central or peripheral nervous system (e.g. spinal cord), a peripheral neuropathy (either diabetic or non-diabetic), multiple sclerosis or a hearing disorder such as tinnitus;
(viii) a method of treatment of a human to treat neuronal degeneration which comprises treating said human with an effective amount of a compound of the formula (I) or with a pharmaceutically acceptable salt, solvate or composition thereof;
(ix) a method of treatment of a human to promote neuronal regeneration and outgrowth which comprises treating said human with an effective amount of a compound of the formula (I) or with a pharmaceutically acceptable salt, solvate or composition thereof;
(x) a method of treatment of a human to treat a neurological disease or disorder such as a neurodegenerative disease which comprises treating said human with an effective amount of a compound of the formula (I) or with a pharmaceutically acceptable salt, solvate or composition thereof;
(xi) a method as in (x) where the neurological disease or disorder is selected from the group consisting of senile dementia (Alzheimer""s disease) and other dementias, amyotrophic lateral sclerosis and other forms of motor neuron disease, Parkinson""s disease, Huntington""s disease, neurological deficits associated with stroke, all forms of degenerative disease affecting the central or peripheral nervous system (e.g. cerebellar-brainstem atrophies, syndromes of progressive ataxias), all forms of muscular dystrophy, progressive muscular atrophies, progressive bulbar muscular atrophy, physical or traumatic damage to the central or peripheral nervous system (e.g. spinal cord), herniated, ruptured or prolapsed intervertebrae disc syndromes, cervical spondylosis, plexus disorders, thoracic outlet syndromes, all forms of peripheral neuropathy (both diabetic and non-diabetic), trigeminal neuralgia, glossopharyngeal neuralgia, Bell""s Palsy, all forms of auto-immune related disease resulting in damage of the central or peripheral nervous system (e.g. multiple sclerosis, myasthenia gravis, Guillain-Barrxc3xa9 syndrome), AIDS related disorders of the nervous system, dapsone ticks, bulbar and retrobulbar affections of the optic nerve (e.g. retinopathies and retrobulbar neuritis), hearing disorders such as tinnitus, and prion diseases;
(xii) a method as in (xi) where the neurological disease or disorder is senile dementia (Alzheimer""s disease) or another dementia, amyotrophic lateral sclerosis or another form of motor neuron disease, Parkinson""s disease, Huntington""s disease, a neurological deficit associated with stroke, physical or traumatic damage to the central or peripheral nervous system (e.g. spinal cord), a peripheral neuropathy (either diabetic or non-diabetic), multiple sclerosis or a hearing disorder such as tinnitus; and (xiii) any novel intermediates described herein.